今日作业如下：
安装gcc
首先先检查一下是否有gcc（虽然一般都没有）
gcc --version
然后就会报错（啊好还没装呢）
然后输入
sudo apt-get install build-essential
再输入一次查看
gcc --version
hello.c
新建一个文件夹放作业
mkdir CaoZuoXiTong
cd CaoZuoXiTong
输入进入hello.c进行编辑
vim hello.c
输入i进入insert模式写入代码：
#include <stdio.h>
int main(){
printf("Hello World!skeptical");
return 0;
}
然后按esc键和shift+：键输入wq保存.
输入
gcc hello.c -o hello
./hello
fork.c
在终端中输入vim fork.c
同样输入
#include <sys/types.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
int main(){
pid_t pid;
pid = fork();
if(pid < 0) {
fprintf(stderr, "Fork Failed");
exit(-1);
}
else if (pid == 0) {
execlp("/bin/ls","ls",NULL);
}
else {
wait(NULL);
printf("Child Complete\n");
exit(0);
}
}
保存退出后再在终端中输入
gcc fork.c -o fork
./fork
processes.c
继续
vim processes.c
输入
#include <sys/types.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
int value;
int main(){
pid_t pid;
pid = fork();
if (pid < 0){
fprintf(stderr, "Fork Failed");
exit(-1);
}
else if (pid == 0) {
for(;;){
printf("In child process, value is %d\n", value++);
printf("In child process, value's address is %p\n", &value);
sleep(1);
}
}
else {
for(;;){
printf("In parent process, value is %d\n", value);
printf("In parent process, value's address is %p\n",&value);
sleep(1);
}
}
}
可以用ctrl+c中断
communication.c
输入
vim communication.c
输入
#include <sys/wait.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
void SignHandler1(int iSignNo);
void SignHandler2(int iSignNo);
int child1,child2;
int filedis[2];
int main(void){
char buffer[40];
char info[40];
int status;
int counter = 1;
printf("Process Parent pid %d\n",getpid());
//创建无名管道
if(pipe(filedis) < 0){
printf("Create pipe failed\n");
return -1;
}
//设置软中断信号SIGINT
signal(SIGINT,SignHandler1);
//创建进程1,2
child1 = fork();
printf("child1=%d\n", child1);
if(child1 == 0){
//子进程1
printf("Process1 pid %d\n",getpid());
signal(SIGINT,SIG_IGN);
signal(SIGUSR1,SignHandler2);
while(1)
{
close(filedis[0]);
sprintf(info,"I send you %d times",counter);
write(filedis[1],info,30);
counter++;
printf("PID: %d, I have sent.\n", getpid());
sleep(1);
}
}
else if(child1 > 0){
child2 = fork();
if(child2 == 0){
printf("Process2 pid %d\n",getpid());
signal(SIGINT,SIG_IGN);
signal(SIGUSR1,SignHandler2);
while(1){
close(filedis[1]);
read(filedis[0],buffer,40);
printf("PID: %d, I received: %s\n",getpid(),buffer);
}
}
//等待进程1,2退出
waitpid(child1,NULL,0);
printf("Child Process1 is over\n");
waitpid(child2,NULL,0);
printf("Child Process1 is over\n");
//关闭管道
close(filedis[0]);
close(filedis[1]);
printf("Parent Process is killed!\n");
}
return 0;
}
void SignHandler1(int iSignNo){
printf("\nParent receive signal Ctrl+C\n");
if(iSignNo == SIGINT){
kill(child1,SIGUSR1);
kill(child2,SIGUSR1);
}
}
void SignHandler2(int iSignNo){
close(filedis[0]);
close(filedis[1]);
if(child1 == 0 && iSignNo == SIGUSR1){
printf("Child Process1 is killed by Parent!\n");
exit(0);
}
if(child2 == 0 && iSignNo == SIGUSR1){
printf("Child Process2 is killed by Parent!\n");
exit(0);
}
}
输入
gcc communication.c -o communication
./communication
完成啦，今天又买了炭烧，这次是胀气debuff，大无语。
陈老师真的好可爱，下课还嘟哝位子上蚊子多。